Continued work on our general synthesis of the alpha-methylene lactone group is proposed. Particular attention will be paid to the exploitation and further development of our just-discovered cyclocarbonylation catalyst (PdC12/2Ph3P/stannous chloride in anhydrous CH3CN) as a means of transforming acetylenic alcohols into methylene lactones. Methodology for preparing the required acetylenic alcohols will also be further developed. Effects of donor solvents on the regioselectivity of ethynyl alane reagents in their reactions with epoxides will be determined. Several fragmentation reactions will be explored as routes to 3-ethynyl alcohols and therefore to alpha-methylene-gamma-lactones. Other potential palladium cyclocarbonylation catalysts will be screened and a synthesis stoichiometric in Pd, employing Pd(O) and chloroformates of appropriate unsaturated alcohols, will be developed for certain unsaturated lactones difficult to make catalytically. Extensions of these catalytic and stoichiometric methods should lead to the development of new synthetic methods for saturated and unsaturated lactones of the types found in many physiologically active natural products.